Friday 7th March, Everglades Wetland Research Park and Ten Thousand Islands, Everglades National Park

27C, 81% humidity
Another early start brought us to the Everglades Wetland Research Park in Naples, at the Naples Botanical Garden. A research and teaching facility, it is under the jurisdiction of the Florida Gulf Coast University and largely focuses on water quality improvement in wetland habitats. The centre offers short courses in wetland restoration, wetland ecology and management, and hosts researchers from undergraduate students to postdoctoral scholars.

On arrival, we were greeted by Li Zhang, Ph.D who we met briefly at the Corkscrew Swamp Sanctuary.  She outlined much of the research being carried out currently, with projects including:

• Wetlands in the Midwest and Gulf of Mexico
• Water purification of wetlands in the Florida Everglades
• Research into Carbon Sequestration 
• Mangrove restoration in the Naples bay
• Effect of stormwater treatment on phosphorous levels

In the case of Midwestern wetlands, it was found that nitrate levels in the Mississippi River were too high and was resulting in hypoxia in the Gulf of Mexico. Dissolved oxygen was measured at <2.0mg/l, where a healthy system exhibits dissolved oxygen levels closer to 8.0mg/l.  Research at the centre led to the conclusion that management measures such as better handling of fertiliser use (filter strips between farmland and rivers) and large-scale restoration of wetlands and riparian bottomlands were necessary. An estimated 5 million acres of wetlands would be required to regulate nitrate levels in the area.

Staying at the Marine Vester Field Station, seeing the things I did and with the people I did has been one of the best experiences of my life.  It has certainly highlighted to me the importance of wetland ecosystems worldwide, and that much work is still required to sustain and restore them.

Thursday 6th March, Corkscrew Swamp Sanctuary

27C, 96% humidity
The Corkscrew Swamp Sanctuary is host to the largest area of untouched bald cypress forest in North America. It contains peat known to be up to 7,000 years old, and makes up part of the big cypress system within the western everglades. 

On arrival, a short talk on the history of the swamp was delivered:

1. In 1847, a lawyer named Buckingham Smith was charged by the US government with evaluating the Florida everglades and deciding whether draining them was a viable option. After visiting the area, he concluded that it was beautiful - but useless. The Everglades were to be drained.
2. In 1881 Hamilton Disston, a real-estate developer, purchased 4 million acres of land in Florida and subsequently set about draining Lake Okeechobee from the east and the west.  
3. As the early 1900's came around, so did demand for egret and heron plumes that had become fashionable adornments for women's hats. Plume hunters were decimating rookeries across Florida. Among these was the Corkscrew swamp. However, in 1913 Rhett Green was employed as a warden by the Audubon society to protect the birds of Corkscrew swamp, and he did so with his life. 

At the time drainage began, it is estimated that 2.5 million wading birds inhabited the everglades. It is now currently home to just 100,000.

Valuation of restoring the Florida Everglades is approximately $19 billion.

WETLAND PRAIRIE

The oak hammock community is incredibly diverse

Beginning our boardwalk tour, the vegetation transitioned from an oak hammock forest into a wet prairie. Within the oak hammock, the understory is dense and Saw Palmetto has a dominant presence in the community. The canopy is largely made up of Live Oak and Laurel Oak, with the occasional Cabbage Palm. The presence of epiphytes in an oak hammock is common and characteristic, such as Spanish Moss and the Resurrection Fern. 

Wet prairie bordered by pine flatwoods

The wet prairie is flooded anywhere between 3-7 months of the year, and forms the transition habitat between pine flatwoods and cypress forests. It is absent of tree species, and largely dominated by wetland emergent plants and grasses.

CYPRESS SWAMP

A complex system involving ferns and flowering wetland
plants amongst Pond Cypress trees

Moving further onwards, the water level became gradually higher and Pond Cypress began to dominate the area. It was difficult to differentiate between Pond and Bald Cypress trees as both were lacking needles, however Pond Cypress is much smaller and inhabits shallower waters.

Strangler fig,
Ficus aurea

Further still led us to the now familiar Bald Cypress community, wherein we encountered a raccoon and soon after an American Alligator. From a constructed viewpoint using a terrestrial telescope, a group of nesting Wood Storks could be seen. The endangered Wood Stork is a valuable species as they are good indicators of a healthy wetland system, and are easy to count as they are white and nest in trees.

Soon after we completed the boardwalk route, a thunderstorm passed over Corkscrew swamp. Thunderstorms are the primary source of precipitation for wetlands in the wet season.  Lightning is also largely responsible for starting most natural wildfires, a process essential to maintaining ecosytems such as the Pine Flatwoods. Without regular burning, flatwoods would undergo succession and eventually convert to an Oak Hammock.

Wednesday 5th March, The J.N. 'Ding' Darling National Wildlife Refuge

28C, 93% humidity Our visit to The Ding Darling National Wildlife Refuge began with a relatively short drive, on which we passed a small herd of white-tailed deer just before arrival. It is a 5,200 acre area on Sanibel island, encapsulating one of the country's largest undeveloped mangrove ecosystems. It is famed for its migratory bird populations.

FLORIDA FISH AND WILDLIFE CONSERVATION COMMISSION

The Ding Darling Refuge describes itself as like a national park, but fundamentally not one. This is because it is run by an agency based on science, and as they put it, "the wildlife comes first". This agency is the Florida Fish and Wildlife Conservation Commission, which is responsible for 562 national refuges across the United States. The location of these tend to follow the migratory patterns of birds, and 10% of them are not accessible to the public. This is precisely why they are called 'refuges'; they function as an asylum for vulnerable species. In Ding Darling alone, there are an estimated 245 bird species, and it is also a stronghold for the endemic Sanibel island rice rat. 

The wildlife drive is closed on Fridays, in order to carry out essential maintenance and conduct biological surveys. Much of the maintenance undertaken is clearing and removal of abandoned fishing equipment, which can be a great hazard to wading birds and aquatic species. Thanks to this work, bird injuries caused by fishing line is now rare. Plastic bottles are also not allowed on site to reduce litter. 

The refuge is named after the political cartoonist Jay Norwood 'Ding' Darling, who pushed for more conservation through his work. He also drew the original duck stamp, which is required in order to legally hunt migratory waterfowl. It also allows free entrance to National Wildlife refuges, and is considered a collectible item. At $15 each and with 98% of proceeds going towards wetland conservation, it is a significant means of raising funds to protect vulnerable bird species. Much of the money is used to buy and then protect land. 

There are also Elementary and Middle schools attached, totalling at 500 students. The aim is to educate children in the importance of wildlife and the environment. 

MANGROVE SWAMP BOARDWALK

Invasive Cuban tree frog, Osteopilus septentrionalis

After a presentation from one of the rangers, Toni Westland, we were taken on a short tour of the footpaths in amongst the mangrove swamps. There we encountered a Cuban tree frog for the second time on our visit, this time in the hollow of a tree. 

Further on, Toni pointed out otter scat at the side of the path, and signs of a well-used alligator crossing.

This footpath led on to a wooden walkway that extended over the water, creating a handy viewpoint from which bird tracks and large flocks of birds could be observed. 
Here, we encountered a large flock of white ibis, with a number of individuals coming and going at any one time. Just behind them, a pair of anhingas, or snake birds, tended to a nest. Just to the left of the viewing platform, we were lucky enough to see a tri-coloured heron amongst the vegetation. 
Retracing our steps back to the visitor centre, we observed an anhinga exhibiting its characteristic behaviour of swimming with only its neck and head visible above the water.

WILDLIFE DRIVE

We returned to the minivans after lunch to begin our tour of the wildlife drive. For the majority of the journey, the road was flanked by large expanses of water, occupied by flocks of wading birds of considerable size. Wooden viewing platforms with telescopes dotted the route, allowing better observation should one decide to stop for a better look. Our first stop led us through a denser area of mangroves, within which we managed to spot two different species of water snake: the Florida banded water snake and the mangrove salt marsh snake.

Our second stop was at a small sandy area, where within shallow waters an alarming number of horseshoe crabs scuttled. It would appear they were displaying breeding behaviour. During the breeding season, the marine arthropods migrate to shallow coastal waters with sand or mud substrates, most often the same location as that which the individual hatched itself. This is thought to be the reason why it is so difficult to breed horseshoe crabs in captivity.

Our final stop rounded off the day nicely with a field trip highlight. The first and only occasion on which we saw a West Indian manatee in close quarters. It was mid-afternoon by this time, and we found the manatee as it drifted its way around a small side pool off the main body of water. As we stood and watched, it slowly moved back under the bridge and out into open water.

During winter, manatees tend to stay close to warm water during the day in order to conserve body heat, and then venture out to cooler, more vegetated areas to feed later in the afternoon. This would explain the manatee's presence in the small, shaded body of water.

Tuesday 4th March, Loxahatchee National Wildlife Refuge

28C, 100% humidity
On Tuesday we made an especially early start, in order to travel across state to The Loxahatchee National Wildlife Refuge. This is a 147,392 acre wildlife sanctuary that encompasses the northern vestige of the original Florida everglades wetland system. It offers public recreational and educational facilities as well as functioning as a refuge for native wildlife. It is almost entirely made up of Everglades marsh habitat, with a 400-acre bald cypress swamp constituting the rest.

BALD CYPRESS SWAMP

Resurrection ferns on the
branches of cypress trees

Our first port of call was the boardwalk through the swamp. Almost immediately after entrance, we observed resurrection ferns at around head height, growing in amongst the bald cypress trees. It is an epiphyte, gaining nutrients largely from the air and from water and nutrients that collect on the surface of the host tree's bark. It is most commonly found on cypresses but has been found occasionally on rocks and dead logs. 
We also made out a catbird call - one of many more northern birds that visit the area for the fair climate. We also heard a small group of pileated woodpeckers in the canopy, both their call and drumming.
A small Brazilian pepper tree was found within the swamp, an invasive species brought to Florida from South America as an ornamental plant. Millions have been spent by the government trying to remove them. Melaleuca (which we encountered yesterday) is also found here, after they were introduced to Florida to help stabilise the banks of waterways. Their tendency to drop their seeds at the first sign of stress (ie. any attempt at removal or burning) makes them a difficult species to control, however moths have recently been released as a biocontrol method. At this point, it is too soon to tell whether the moths are having any real effect on the Melaleuca populations. 
Plants are not the only type of invasive species in Florida; the state plays host to approximately 50 species of exotic fish in its waterways as well.
Further along the boardwalk, we regarded a Southern Leopard frog, one of the native tree frog species under threat from the presence of the Cuban tree frog. 
After leaving the cypress forest, we were shown a short presentation on the everglades and the wetland research currently being carried out at the reserve. Much of the work in progress at the moment by the United States Fish and Wildlife Service here is to reverse the effect of phosphorous enrichment in the Everglades. 
One such research project is LILA: Loxahatchee Impoundment Landscape Assessment. LILA is a 80 acre model of the Everglades, allowing researchers to attempt restoration methods within this 'living laboratory' before applying them to the Everglades themselves.

WETLAND MARSH

Moving onto the second area of the refuge, we saw alligators - one adult and a number of juveniles - in a roadside ditch pool. The opposite pool was teaming with sailfin mollies, with large colourful males actively displaying to smaller females. Sailfin mollies thrive in shallow surface waters, such as the ditch we observed them in today, as well as swamps, estuaries and marshes. They are also incredibly tolerant of both high salinity and low oxygen environments. 

American Alligator, Alligator mississippiensis

Within the marsh area, we observed a number of wading/wetland birds:

• Little Heron (sub-group of the green-backed herons)
• Blue-Winged Teal
• Glossy Ibis
• White Ibis
• Great Egret
• Little Blue Heron
• Turkey Vulture
• Anhinga

One other notable plant species found in the reserve is the water hyacinth. Despite being an invasive species and pest throughout Florida, it serves an important purpose within Loxahatchee. The water hyacinth's root colour changes dependent on various nutrient deficiencies, and so is a valuable indicator species of water quality.

Juvenile Eastern Lubber grasshopper showing
yellow colouration

We also encountered a large number of juvenile Eastern Lubber grasshoppers, exhibiting yellow and orange colouration, which are found throughout Florida. In the case of this species, eggs require a number of months of cool weather, and then hatch in the event of higher temperatures. Florida was experiencing a heat wave whilst we visited, which may explain slightly premature hatching of the grasshoppers in such large numbers.

Monday 3rd March, Florida Gulf Coast University Campus

28C, 86% humidity 
Setting off relatively early, on Monday we visited the FGCU campus. The campus has an area of 1 square mile, with approximately 50% of that set aside as protected reserve and conservation areas. 
One of the professors at the university - Wynn - graciously gave us a tour of both the environmental and academic sites on campus. Wynn is a systems ecologist, studying the effect of drought, hurricanes, forest fires etc. on the natural environment. He also works in reconciliation ecology, which involves management of urban areas to make them more environmentally sensitive. For example, the construction of the university and subsequent draining of the land created water flow issues, causing flooding in nearby residential areas. Proper management and changes to the site has reduced this effect and water is now discharged properly and safely from the area. 

ARTIFICIAL WETLAND

Sawgrass wetland area in the
foreground with drier upland behind

We first were shown an artificially constructed wetland, maintained by ecologists like Wynn at the university. Around the edge of the wetland, we encountered Cabbage palm - also known as the Florida state tree. Cabbage palm is a useful, hardy tree that is well known for withstanding hurricanes when many other tree species do not. Its fruit ('swamp cabbage') is also edible, and wiry fronds that grow between the leaves were often utilised by Native Americans to make into twine. Within the leaves of the tree we spotted a cuban tree frog, an invasive amphibian known to outcompete the native tree frog species.
Moving slightly further into the wetland, we encountered bayberry, a native shrub that emits a waxy substance used to make candles.
The majority of the wetland was made up of saw grass, a species that also covers most of the Florida everglades. In amongst this area, we spotted white-tailed deer tracks. White-tailed deer are capable of inhabiting a wide array of habitats, from the saw grass swamps here in Florida to the thornbrush deserts of Mexico.
Moving on to a drier upland area, it was noted that with the stark change in vegetation there was only a 20cm difference in elevation between this and the wetland area. Florida's wetlands provide a clear example of how the water table can drastically affect habitat type.
Within this upland area, we were shown the South Florida slash pine. This tree is incredibly well adapted to forest fires, more so than its Northern counterpart. In the event of contact with fire, the bark will splinter, peeling off and flying away from the trunk. This is thought to transfer heat energy away from the tree. The variety is also fire-resistant at the grass-seedling stage, as a dense tuft of needles protects the terminal bud. 
Since the university opened, there have been two wildfires and two controlled burns on campus as an essential management measure. 
Melaleuca was another species identified in the upland area. Melaleuca is an incredibly successful invasive species, as its massive seed production allows for a dense monoculture to form. It is even thought that fire, which has been used as an attempted control measure, can cause the seeds to spread further. However, Melaleuca is also commonly known as tea tree, and has valuable antiseptic qualities. It also produces an incredibly termite-resistant mulch, and so the waste produced after management at least has its uses.

BALD CYPRESS SWAMP

Moving on to another area of the campus, we approached the cypress forest and swamp area. Here we encountered our second palm species of the day: Saw palmetto. One way in which this species differs from cabbage palm is in that its leaves form a rounded fan from the stem, whereas the cabbage palm's leaves are arranged around an extension of the petiole, or a 'costa'. The saw palm is commonly found in the undergrowth of pine forests, and so its presence near the bald crypress forest is unsurprising. Extract of saw palm is said to help alleviate the symptoms of and prevent prostate cancer, however large clinical studies have shown no known medical effect.
A number of wild flowers were identified, such as swamp pink, purple stargrass and penny royal - which smells of peppermint.
Venturing further into the bald cypress forest (so named as it drops its needles so early in the season - an odd feature for an evergreen tree), it was pointed out to us that the smallest trees are found on the outer edge, getting gradually taller until the very centre at which the trees become shorter again. This is because the ground is more dry on the outside, getting closer to optimal moisture the further into the forest you get, until the centre where water levels are too high and growth is limited again.
Deep into the swamp, cypress knees project from the swamp floor. It is believed that they have a double function: they help to oxygenate the roots of the tree, and also lock together with neighbouring trees to help anchor the population during hurricanes and similar severe weather. 

Cypress swamp, with a clear watermark on the trunks of trees
indicating the water level during the wetter months

Traps set in a nearby lake yielded mosquitofish, golden topminnow and bluefin killifish.

Bluefin killifish

Sunday 2nd March, Lovers Key State Park

26C, 48% humidity
Our first full day in Florida consisted of a visit to Lovers Key State Park, a 712 acre area of land made up of a network of canals and tidal lagoons, edged by mangrove forests. 

We left the Marine Vester field station at around 9 a.m. Sunday morning, and were treated to the sight of a Bald Eagle in flight during the journey.
On arrival, we spotted a pair of Brown Pelicans flying through the park. With nesting behaviour peaking in March-April, this may well have been a breeding pair observed together.

BLACK ISLAND

One of the many waterways in Lovers Key, shortly
before the manatee was sighted

Venturing further into the park, we stopped briefly to observe one of the many waterways from a bridge, where we sighted our first West Indian Manatee - systematically breaking the water first with its head, back, then tail. 

Moving on to a more terrestrial area of the park, we followed a suggested pathway through the vegetation. Here we saw the first (of many) invasive brown anoles on the trip. The brown anole is native to both Cuba and The Bahamas, and these two subspecies (sagrei and ordinatus) have now undergone extensive intergradation and are no longer distinguishable from one another in Floridian populations. They first appeared around the major ports of south Florida, suggesting they were introduced via boats. It has been suggested that brown anoles are primarily responsible for a reduction in populations of green anoles, as they have been observed displacing them from trees, and occasionally by predating upon smaller green anoles.

Shortly after this, a native green anole was sighted soon after having caught a snail. Green anoles are opportunistic feeders - largely insectivorous, but will predate molluscs and at times may feed on grains and seeds. In this instance, the lizard may have been forced to choose a snail due to competition with the brown anole for insect prey, or the green anole may simply be taking advantage of a large population of snails in the area.

Moving on to a more vegetated tract, zebra longwing butterflies were seen amongst the lower brush. The zebra longwing butterfly is the designated butterfly of Florida, and is dissimilar to any other butterfly species within the state and so is easily identifiable. Unusually, it feeds on both nectar and pollen, and the extra nutrients provided by this behaviour allows a lifespan of several months as opposed to the usual 2-4 week lifespan of most butterflies.

Soon after, an Eastern Screech Owl was spotted in the hollow of a royal palm, a non-native tree species. They are known to be occasionally diurnal, and so it being awake at approximately 10 a.m. does not come as much of a surprise.

Opposite, a small group of red-bellied woodpeckers (approximately 5-6 individuals) were seen and heard - distinctive and loud calls were emitted.

After a short walk, a solitary white ibis was observed foraging in a small pool of still water, amongst vegetation.

Gopher tortoise, Gopherus polyphemus

Along this same track, two Gopher tortoises were seen within 5 minutes of each other. Both moved from the middle of the open walkway towards their underground burrows, the likes of which are responsible for the common name of the species. Gopher tortoises are considered a keystone species, and protected under state law. This is due to the importance of the burrows created by the tortoise, which it shares with more than 350 other species.

Between sightings of the Gopher tortoises, we examined a Gumbo Limbo tree, commonly referred to as the 'tourist tree' due to its red and peeling bark. A species native to south Florida, its high salt tolerance makes it well adapted to the brackish waters found around Lovers Key.

MANGROVE SWAMP

After this, we moved to the other side of the park, towards the mangrove swamp area over a series of large wooden bridges. Mangroves belong to the genus Rhizoforasia, which includes 64 species altogether, with only 3 found within Florida. These are the Black, White and Red mangroves. Red and Black species are 'landformers', and are found closer to the sea than white mangroves, with the Red being the closest.
The term 'mangrove swamp' may refer to an area made up exclusively of mangrove species, or may refer to a habitat of brackish water where mangroves are found amongst other salt-tolerant species.
Mangroves do not NEED saline conditions to be successful, however they do outcompete other species and have an advantage in brackish water. However, one condition mangroves cannot withstand is more than a couple of days of sustained frost.